In general, an indexable drill is configured so that a cutting insert may be replaceably mounted on the indexable drill. Thus, when a cutting insert is abraded, a new cutting insert is replaced and used.
As a means for fixing the cutting insert to the indexable drill, a bolt has been used to mount the cutting insert on the indexable drill. However, recently, technologies are being developed so that the cutting insert is autonomously fixed to the indexable drill without using a bolt.
A type in which the cutting insert is fixed to the indexable drill without using a fastening element such as a separate bolt or screw as described above is known as a self-fixing type.
The self-fixing type indexable drill in the related art uses elasticity and frictional force of metal or implements coupling force. In addition, in the case of the self-fixing type indexable drill, concave-convex portions are formed at portions where the cutting insert and the indexable drill are coupled to each other, such that the cutting insert and the indexable drill are coupled to each other as the concave-convex portions are engaged with each other.
However, because a drill tool rotates at a high speed, the cutting insert is required to maintain secure coupling force without being loosened in the indexable drill, during a process of machining a hole.
In a case in which coupling force between the indexable drill and the cutting insert becomes excessively higher, it is difficult to mount or separate the cutting insert.
Therefore, an indexable drill is required to implement coupling force appropriate for fixing the cutting insert and easily separate or mount the cutting insert.
On the other hand, since the cutting insert is a constituent element that performs cutting processing, such that the cutting insert is required to have high rigidity, the cutting insert is manufactured by using an expensive material. In addition, the material is subjected to grinding processing in order to implement a desired shape of the cutting insert, and in this case, it is possible to reduce costs of the cutting insert by reducing parts to be ground and eliminated.
However, a method of manufacturing the cutting insert, which has been known in the related art, has a problem in that a material in the form of a round bar is ground, such that a large number of parts are disposed of, which causes serious material waste.